Telangiectasias are highly prevalent skin disorders. Telangiectasias are visible small, red, purple or blue surface blood vessels that can be located on the face, upper chest, neck or other parts of the body. Telangiectatic blood vessels, which can include swollen blood vessels, spider veins, red dermal patches, purple dermal patches, or blue dermal patches are abnormal and are not necessary for any essential body function.
Telangiectatic blood vessels can appear with or without a preceding or concurrent skin or internal disease. Telangiectasias can develop anywhere within the body, but can be most easily seen in the skin. Telangiectasias include essential or primary telangiectasias, which include blood vessel dilations of unknown etiology. Generalized essential telangiectasias (GET) exhibit a widespread distribution pattern over the body. Other primary telangiectasias include angioma serpiginosum, ataxia telangiectasia, varicose of smaller veins, such as starburst veins, angiomas and spider naevi. Some other examples of conditions, syndromes, diseases and disorders which can include telangiectasia are CREST Syndrome (acronym for Calcinosis, Raynaud's phenomenon, Esophageal dysfunction, Sclerodactyl), and Telangiextasis), hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu Syndrome), ataxia-telangiectasia, rosacea (also known as acne rosacea), basal cell carcinoma, scleroderma, telangiectatic nevus, unilateral nevoid telangiectasia, cutis marmorata telangiectatica congenita, hereditary hemorrhagic telangiectasia. Secondary telangiectasia can develop after actinic damage (such as in erythrosis interfollicularis colli), radiation therapy and as well steroid therapies including chronic corticosteroid treatment. Chronic hepatic and collagen-vascular disorders can also induce telangiectasia.
Telangiectasia can be a symptom of rosacea. However, rosacea also encompasses erythema, and is, accordingly, a phenomenon distinct from a telangiectasia.
Current treatments for ameliorating telangiectasias include laser therapy, light therapy including IPL intense pulsed light, electrocoagulation and electro-optical synergy (ELOS), which combines intense pulsed optical energy and conducted bipolar radiofrequency (RF) energy into a single pulse (Sadick, N S et al., J. Drugs Dermatolog. 4: 181-186, 2005).
Brimonidine, a selective α2-adrenergic agonist, has been used as either a monotherapy or an adjunctive therapy to lower intraocular pressure (IOP) in the treatment of glaucoma and ocular hypertension (OHT) since its approval in 1996. The most common side effects associated with brimonidine therapy are dry mouth, fatigue/drowsiness, headache, mild hyperemia, blurred vision and foreign body sensation. Hypertension, palpitations and syncope have been reported by less than 3% patients in clinical trials involving brimonidine ophthalmic treatment. See McGhie, Journal of the Pharmacy Society of Wisconsin, May/June 2001, at World Wide Web: pswi.org/professional/pharmaco/brimonidine.pdf, and references therein. Results from the dose-ranging study in patients with glaucoma or ocular hypertension showed that although 0.5% (w/w) had higher efficacy in the early phase of treatment, the 0.5% (w/w) and 0.2% (w/w) had similar efficacy after two weeks of treatment, and that 0.5% (w/w) had more systemic and ocular side effects than 0.2% (w/w). See, e.g., Walters, Survey of Ophthalmology, 1996, 41: S19-S26). Ophthalmic formulations containing 0.2% (w/w) brimonidine have been used for chronic applications to treat glaucoma and ocular hypertension, while that containing 0.5% (w/w) brimonidine has been only used for acute therapy for the prevention of postoperative intraocular pressure spikes. In order to reduce a variety of ocular and systemic side-effects associated with the ophthalmic application of 0.2% (w/w) brimonidine, ophthalmic formulations containing lower concentrations of brimonidine, e.g., 0.15% (w/w) or 0.1% (w/w), have been subsequently developed and used for chronic ophthalmic applications.
Brimonidine has been reported to be useful in treating telangiectasias. See, e.g., U.S. Pat. No. 7,838,563 to DeJovin et al. Brimonidine has also been reported to be useful in treating erythema caused by rosacea. See, e.g., U.S. Ser. No. 10/853,585 to DeJovin et al. To ensure the safety and avoid unacceptable side effects, a previous clinical study used 0.2% (w/w) brimonidine tartrate as the “high” dosage for treating erythema. See US 2009/0061020 to Theobald et al.
In the present invention, it has been surprisingly discovered that topical administration of brimonidine to an affected skin area resulted in significantly less systemic exposure to brimonidine than topical ophthalmic application of brimonidine. It has been found that although systemic exposure increased with the applied dose of brimonidine, statistical analysis showed that the increase in systemic exposure (Cmax) was not dose proportional, e.g., the increase in the mean Cmax was much less than the increase in the dose. It has also been discovered that, unlike the topical ophthalmic application of brimonidine, topical administration of higher than 0.2% (w/w) brimonidine to a skin area affected by telangiectasias or a related symptom resulted in increased efficacy without observable loss of effectiveness over time. No unacceptable drug related adverse events was observed with the treatment of higher concentration of brimonidine tested.
Accordingly, a higher concentration of brimonidine, such as about 0.3% (w/w) to about 10% (w/w), can now be used in improved methods and compositions for safe and effective treatment of telangiectasias or a symptom associated therewith.